Search results with tag "Acoustic impedance"
Chapter 12:Physics of Ultrasound - Human Health Campus
humanhealth.iaea.orgA reflection is produced when an acoustic wave encounters a difference in acoustic impedance , so an ultrasound image may be thought of as a map of the relative variations in acoustic impedance in the tissues −1 ≤R≤1 A negative value of R implies that the reflected wave is inverted with respect to the incident wave Z is the acoustic impedance
Ultrasonic testing useful formulae - Trinity NDT
www.trinityndt.com2011-12 Page 2 of 4 4. Transmission coefficient T = 4 Z1Z2/ (Z1+Z2)2 Where: R = Reflection Coefficient Z1 = Acoustic Impedance of Medium 1 Z2 = Acoustic Impedance of Medium 2 5. Longitudinal Wave Velocity Where: VL = Longitudinal Wave Velocity E = Modulus of Elasticity
Part 3 REFLECTION AND TRANSMISSION OF ULTRASONIC …
www.fast.u-psud.frThis means that perfect matching (total transmission and zero reflection) can be achieved even between widely different impedances if a quarter-wavelength matching layer of ZZZo = 12 acoustic impedance is applied at the interface. Let us denote the center frequency where the layer thickness equals to one quarter-wavelength by fo. In the ...
DIGEST Guidelines - Shockwave Therapy
www.shockwavetherapy.orgTransmission (transverse wave, longitudinal wave) (Partial) reflection Diffraction and / or deflection, scattering Wave velocity x density of the medium = acoustic impedance Pressure / tension wave, shear forces
ReView ARticle Imaging Artifacts in Echocardiography
www.asecho.orgvelocity of sound waves in the tissue. Differences in acoustic impedance cause reflections (echoes). Absorption The conversion of sound energy to heat as it travels through a medium. Attenuation The gradual loss of ultrasound energy as the wave propagates through tissue; it is caused by reflection, scattering, and absorption.
Ultrasound Imaging System - University of California, Los ...
www.ccn.ucla.eduReflection and transmission ! Acoustic impedance : Z=ρc ! ρ: density, c : sound velocity Z 1 Z 2 θ i θ r θ t Incident wave Reflected wave Transmitted wave 2 1 sin sin c c t i = θ Snell’s law θ R p= Z 2cosθ i−Z 1cosθ t Z 2cosθ i+Z 1cosθ t T p= 2Z 2cosθ i Z 2cosθ i+Z 1cosθ t For sound pressure R p: reflectance, T p ...
ACOUSTIC METAMATERIAL DESIGN AND APPLICATIONS BY …
web.mit.educonsidering the acoustic impedance é ? of aluminum is around eleven times of that of water. A more careful analysis including elasticity of the solid suggested that at low frequency the majority of acoustic energy can be predominantly confined in the fluid, when such an excitation